Modulation of Solid-State Aggregation of Square-Planar Pt(II) Based Emitters : Enabling Highly Efficient Deep-Red/Near Infrared Electroluminescence

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Chattarika Sukpattanacharoen
  • Wei-Hsiang Chan
  • Chun-Chi Huang
  • Hsiu-Fu Hsu
  • Wen-Yi Hung
  • Nawee Kungwan
  • Daniel Escudero

Detail(s)

Original languageEnglish
Article number2002494
Journal / PublicationAdvanced Functional Materials
Volume30
Issue number25
Online published30 Apr 2020
Publication statusPublished - 18 Jun 2020

Abstract

The design of square-planar Pt(II) complexes with highly efficient solid-state near infrared (NIR) luminescence for electroluminescence is attractive but challenging. This study presents the fine-turning of excited-state properties and application of a series of isoquinolinyl pyrazolate Pt(II) complexes that are modulated by steric demanding substituents. It reveals that the bulky substituents do not always disfavor metallophilic Pt center dot center dot center dot Pt interactions. Instead, pi-pi stacking among chelates, which are fine-tuned by the associated substituents, also exerts strong influence to the metal-metal-to-ligand charge transfer (MMLCT) transition character. Theoretical calculations indicate that Pt center dot center dot center dot Pt contacts become more relevant in the trimers rather than the dimers, especially in their T1 states, associated with a change from mixed 3LC/3MLCT transition in the monomer/dimer to mixed 3LC/3MMLCT transition character in the trimer. Electroluminescence devices affording intense deep-red/NIR emission (near 670 nm) with unprecedentedly high external quantum efficiency over 30% are demonstrated. This work provides deep insights into formation MMLCT transition of square-planar Pt(II) complexes and efficient molecular design for deep-red/NIR electroluminescence.

Research Area(s)

  • near-infrared phosphorescent emitters, organic light-emitting diodes, Pt(II) complexes, solid-state aggregation, trimers, LIGHT-EMITTING-DIODES, ACTIVATED DELAYED FLUORESCENCE, EXTERNAL QUANTUM EFFICIENCY, PLATINUM(II) COMPLEXES, LUMINESCENCE, PHOSPHORESCENCE, EMISSION, STACKING, LIGAND, RED

Citation Format(s)

Modulation of Solid-State Aggregation of Square-Planar Pt(II) Based Emitters : Enabling Highly Efficient Deep-Red/Near Infrared Electroluminescence. / Chen, Wen-Cheng; Sukpattanacharoen, Chattarika; Chan, Wei-Hsiang; Huang, Chun-Chi; Hsu, Hsiu-Fu; Shen, Dong; Hung, Wen-Yi; Kungwan, Nawee; Escudero, Daniel; Lee, Chun-Sing; Chi, Yun.

In: Advanced Functional Materials, Vol. 30, No. 25, 2002494, 18.06.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review